Hi, thanks for the comment, I really couldn't see any other way around it to be honest!
Another thing to bear in mind to anyone else in this situation, is the rear sump caulk oil seal which runs around the rear main bearing carrier is also different, its smaller than the later engined ones, so the ones provided in the gasket kit don't fit, all I did was cut it to the right length and sand the edges down on a belt sander so it was the correct width to fit in the groove. It looked the same size as the front sump oil seal but I couldn't do with messing about!
Another problem I had which looks like a slight manufacturing fault is, on the new conrod I had to have, the shoulder of the bearing cap bolt protruded slightly so it wouldnt fit down the bore, I had to file a bit off it so it would fit down. Luckily though one of the jobs - a new oil pump - couldn't have been easier to fit, it was exactly the same in every way, I bought it off ebay from agripartsuk, would highly recommend them, very helpful, and with postage it came to £38 I think - not bad.
Going by the manual ive got which was downloaded from fordsondexta.de, and very kindly sent by jerry coles of this forum, my engine is the original , which is nice, but not so when you hit snags like these sometimes, hopefully the rest of the assembly will be fairly straight forward.

Oh yay, look, another seized bolt! Lets get a hammer.....and some kano.....and some cider!